A mobile device such as a mobile telephone, pager, PDA, or any wireless device has one or more home networks with which the mobile device will normally connect. Within a home network, the mobile device is able to obtain services based upon a monthly fee structure with or without a use-based fee structure. When leaving their home network or when unable to contact their home network, the user loses the ability to establish connections using their mobile device. In order to overcome this problem, network providers have entered into various roaming agreements. Roaming agreements enable users from one network to visit other networks and still obtain connectivity for their mobile device even when they are unable to contact their home network or are located outside of their home network (i.e., roaming).
In order to provide connectivity over large areas of the country, outside of a user's home network, home network providers often have a number of roaming agreements with a variety of different networks over the entire country. This requires the implementation of a preferred roaming list (PRL) within a given system, or similar type of priority list within other types of wireless systems, within the mobile device that provides the mobile device with a priority order for connecting to various roaming partners of the home network provider.
When attempting to register with a network to provide connectivity to the mobile device, the mobile device initially determines the signal strength of all the networks within the range of the mobile device. If the home network is providing sufficient signal strength, the mobile device will connect with the home network and provide calls and connectivity through the home network. However, in a situation where the home network is unable to provide sufficient signal strength to the mobile device, the mobile device determines the roaming partner of the home network to which the mobile device should connect.
To do this, the mobile device will examine the preferred roaming list and select the roaming partner having the highest priority on the referred roaming list that has a sufficient signal strength for connecting with the mobile device.
Currently, CDMA handsets use the preferred roaming partner definitions within the PRL in order to select the roaming partner when the home network is unavailable. LTE devices roaming without enhancement base roaming selection on static definitions on the USIM (Universal Subscriber Identity Module). A problem that may occur with the use of the PRL-type list arises from camping on a roaming partner's network when there is poor or no coverage from the home network. Current selection of roaming partners from a PRL are non-intelligent and always select a same roaming partner regardless of time and location or any other criteria. In certain locations and at certain times, a home network provider's capacity may be limited by available spectrum or network congestion, and the home network provider would like the ability to control the use of roaming partner network selections in order to alleviate this problem.